With the continued improvements in body armor, and the disturbing increase in explosive offensives in modern combat, more of our wounded soldiers are surviving their injuries and there has been a considerable increase in the military amputee population. Improvements in the prosthetic limb dynamics have outpaced improvements to the fit and comfort of the devices, and so several concerns remain as to the interface to the residual limb and the resulting physical demands on the amputee. Most systems designed to measure energy expenditure do so through a face mask that monitors oxygen consumption. This is too cumbersome to be appropriate for the military"s need. More recent systems utilize body sensors but are not appropriate or accurate for amputees. Infoscitex Corporation and Liberating Technologies, Inc. are developing a system that monitors additional expenditure based on gait, and is wholly embedded in the socket. The Advanced Metabolic Energy Monitoring Socket (AMEMS) system will track the motion of the user"s lower limbs and monitor the exertion of key muscle groups during the performance of tasks during rehabilitation in order to arrive at an accurate assessment of biomechanical efficiency and energy expenditure. Ultimately, a prescribed intervention could be modified until it improves energy expenditure for the amputee, thereby increasing quality of life.